Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016

Bibliographic Data

ID15545273
AuthorsXuesong Zhang (0000-0002-7295-9304, Joint Global Change Research Institute), Tyler J Lark (0000-0002-4583-6878, University of Wisconsin–Madison), Christopher M Clark (0000-0002-4716-4155, Environmental Protection Agency), Yongping Yuan (0000-0002-6843-3342, Environmental Protection Agency), Stephen D LeDuc (0000-0003-2908-0000, Environmental Protection Agency, corresponding author)
Year2021
Volume16
Issue5
Pages054018-054018
Publication date2021-05-01
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueEnvironmental Research Letters (JOURNAL)
Journal identifiersISSN: 1748-9326 • E-ISSN: 1748-9326
PublisherIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/abecbe
PMID36560928
OpenAlexW3160922381
LanguageEN
Citations received6
References cited34

After decades of declining cropland area, the United States (US) experienced a reversal in land use/land cover change in recent years, with substantial grassland conversion to cropland in the US Midwest. Although previous studies estimated soil carbon (C) loss due to cropland expansion, other important environmental indicators, such as soil erosion and nutrient loss, remain largely unquantified. Here, we simulated environmental impacts from the conversion of grassland to corn and soybeans for 12 US Midwestern states using the EPIC (Environmental Policy Integrated Climate) model. Between 2008 and 2016, over 2 Mha of grassland were converted to crop production in these states, with much less cropland concomitantly abandoned or retired from production. The net change in grassland-cropland conversion increased annual soil erosion by 7.9%, nitrogen (N) loss by 3.7%, and soil organic carbon loss by 5.6% relative to that of existing cropland, despite an associated increase in cropland area of only 2.5%. Notably, the above estimates represent the scenario of converting unmanaged grassland to tilled corn and soybeans, and impacts varied depending upon crop type and tillage regime. Corn and soybeans are dominant biofuel feedstocks, yet the grassland conversion and subsequent environmental impacts simulated in this study are likely not attributable solely to biofuel-driven land use change since other factors also contribute to corn and soybean prices and land use decisions. Nevertheless, our results suggest grassland conversion in the Upper Midwest has resulted in substantial degradation of soil quality, with implications for air and water quality as well. Additional conservation measures are likely necessary to counterbalance the impacts, particularly in areas with high rates of grassland conversion (e.g., the Dakotas, southern Iowa)

Agroforestry · Agronomy · Carbon dioxide · Carbon sequestration · Grassland · Land use · Land use, land-use change and forestry · Soil carbon · Soil Quality · Soil water · Tillage · Bioenergy crop production and management · Environmental Science · Soil Carbon and Nitrogen Dynamics · Soil erosion and sediment transport · Ecology · Soil Science

Tools

Open DOIOpen Access